Reaction process



w. DAVEY REACTION PROCESS Nov. 20, 1945.

5 Sheets-Sheet 1 INVENTOR WMM/v Az/fy ATT Filed May l5, 1941 BY ORNEYNov. 20, 1945.

W. D AVEY REACTION PROCESS Filed May 15, 1941 5 Sheets-Sheet 2 INVENTOR#M4/QM m/fy ATTORNEY NOV. 20, 1945. W DAVEY 2,389,246

REACTION PROCESS Filed May 15, 1941 5 sheets-sheet :s

, ATTORNEY Nov. 2o, 1945. W DVEY 2,389,246

REACTION PROCESS Filed May 15, 1941 5 Sheets-Sheet 4 INVENTOR l/MQRf/yDA1/fr BY Z l ATroRNEy '5 snQet-sheet 5 Fld May 15, 1941 INVENTOR ll/l//wRf/v @A1/fr BY f 2 ATTORNEY Patented Nov. 20, 1945 www 2.389.240monos raocnss Warren Davey, Montclair, N. J., signor toColgate-Palmolive-Peet Company. Jersey City. N. J.. a corporation oiDelaware Application May 15, 1941, Serial No. 893,9

' 'I momma. (ce zoo-41s) roded when brought into contact imderstressror", 4-

This invention relates to an improved process for hydrolyzing fats andoils and to novel apparatus suitable for use in this improved process.and more particularly to an improved process and novel apparatus forcountercurrent hydrolysis of fats and oils.

The process of this invention is an improvement of the process disclosedin United States Patent No. 2.1395589 which issued to Martin H. Ittner.That patent discloses and claims a process for countercurrent hydrolysisoi fats and oils, continuous or intermittent, in which the temperatureof reaction is above about 200 C. and the pressure is suiilcient tomaintain the material in a liquid state, i. e.. the pressure is equal toor in excess of the pressure of saturated steam at the temperatureemployed. Another United States patent, No. 2,156,863, containsdisclosures similar to the Ittner patent but is limited to a continuous,counter-current hydrolysis of fats and separately preheating the waterand oils or fats.

Development oi processes involving high temi peratures and pressureshasincreased the necessity for vessels and apparatus which have greatercorrosion resistance, since it has been found that acids and otherchemicals which are generally inactive at low temperatures and pressuresare very active at high temperatures and pressures and readily attacknormally corrosivehresistant metals.

In attempting to overcome these objections and.

about one and one-half times the linear `coeifllcient of expansion ofcarbon steel, consequently in a vessel seventy feet long, subjected to atemperature of 250 C., the liner, if free to expand, would expand aboutan inch in length more than the outer layer of carbon steel.

Such a condition would set up excessive strains in the outer shell andinstances ci severe buckling and ultimate breakdown of the inner layerhave occurred; also, the stresses induced in the inner strain with suchchemicals at high temperatures' -and pressures. lEven fatty acids. suchas those employed in the manufacture of soap, become soactive at hightemperatures that they attack metals -or4 alloys under stress or strainwhich would remain substantially resistant thereto in the absence ofsuch stress or strain.

Moreover. in a plant which is now being I' in hydraulic shock is avoidedor controlled.

layer would tend to lessen its corrosion resistant properties.

Furthermore, alloys which ordinarily are resistant to the action ofacids are seriously cor- Another object of my invention is to provide aprocess for the hydrolysis of fats and oils wherein the surface of theliquid is in contact with steam.

A further object of my invention is to provide a vessel having improvedcorrosion resistance.

A still further object is to provide a corrosion resistant vesselwherein the pulsation of the pumps and other shocks are cushioned sothat processes may be carried out therein with increased regularity andsafety.

Other objects will present themselves to those skilled in the art es thedisclosures are read.

The manner of accomplishing the objects of my invention with respect tothe process will be understood better by considering rst the manner ofachieving the objects of the apparatus, the operation of which willillustrate the process.

Referring now to Figure 1, the pressure vessel I is preferably a carbonsteel shell designed for high working pressure, tltted with a cover 2vhaving a suitable sealed joint for withstanding the high pressure, theentire inner surface of the vessel to be clad with a relatively thinlayer of a corrosion `resistant alloy 3 having substantially the samecoeiiicient of linear expansion as the carbon steel shell. For thiscorrosionresistant layer, I prefer to use a chromium-nickei-iron alloyknown as Incone1" which contains approximately the followingcomposition: nickel. 79.0 to 80.0%; chromium, 12.5 to 13.5%; iron, 6.0to 7.0%: manganese, 0.2 to 0.3%: silicon, 0.2 to 0.3%: copper, 0.15 to0.25%; carbon, not more than 0.15% Other corrosion resistant metals oralloys with the proper coefficient of expansion vmay be used. 'Ihelfunction of this lining will be described later.

The reaction portion of the apparatus consists 2 a,sse,24c

' legs 5, preferably not fastened to the outer shell,

and is free to move either circumferentially or longitudinally, withoutat any time coming in contact with the outer shell and therefore is notsubject to any stress or strain other than the weight of the liquid heldtherein.

The construction of the bottom of the inner tank 4 is so designed thatthe supporting legs 5 and the connecting pipes 6 and 1 are ofsubstantially the same length and of the same material or of materialshaving substantially the same coefilcient of expansion, so that as theybecome heated there will be practically no differential in their length,due to expansion.

However, if it is thought advisable, the pipes B and 'I passing throughthe outer shell may be provided with stuiilng boxes and glands or othermeans or may be more or less curved to permit of movement relative tothe outer shell, should any occur, and also provide easy access forremoval of the inner shell, should occasion require it.

The outer carbon steel shell I is tted with a trough 8, connected todrain pipes 9; and the inner shell 4 is fitted with an inverted collarI0 which ts loosely into the trough 8. This construction is clearlyshown in Figure 2.

Drain pipes 9 are connected to a common receiver (not shown) fitted witha bleeder valve and suitable drainage connections. If live steam Y beadmitted into the outer shell through pipe II,

it will be apparent that as the entire apparatus heats up. the innershell 4 is free to expand and as the entire system becomes filled withsteam,

pressure may be applied up tothe desired working pressure, without theinner shell being subjected thereby to pressure strains.

If the bleeder valve on the receiver above mentioned be left slightlyopen, there will be a continuous flow of steam past the inverted collarIII, downwardly through trough B and outwardly through pipes 9, thustending to prevent the passage of any corrosive liquids or gasesbackwardly and down into the annular space I2 between the inner andouter shells. Any condensate formed in this annular space I2 will flowout through pipe I3 to a trap (not shown) and this will prevent anytendency of buoyance in inner shell 4.

I prefer to operate the apparatus with the liquid level I4 somewhatabove the lower end of outlet pipe I5, appreciably above the end of pipeI6, and well below the upper rim I1 of the inner vessel or open top tank4. The space above the liquid level I4 and the annular space I2 are lledwith steam at a pressure that will prevent any objectionable i. e. anysubstantial evaporation of the water in vessel 4, and will maintain thereacting fatty material and water as liquid phases.

It has long been known that when the surface of a liquid is exposed toany space that is not v already lled with the saturated vapor of thatliquid, e. g., a space filled with vapor at a pressure lower than thepressure of saturated vapor at the temperature of the liquid, vapor isgenerated from the liquid until the space is filled with Y Vf' lsaturated vapor in temperature-pressure equilibrium with the liquid(unless the liquid present is insumcient to generate the required amountof vapor). In reaching this equilibrium, the pressure of the vapor inthe space rises due to the generation of vapor and the temperature ofthe liquid drops due to the abstraction of heat utilized in changing theliquid into vapor, the drop in temperature depending upon the amount ofvapor generated and the amount of outside heat, if any, that issupplied. It has also long been known, on the. other hand, that when thesurface oi a liquid is exposed to any space that is filled with vapor ofthat liquid at a pressure higher than the pressure of saturated vapor atthe temperature of the liquid, vapor is quickly condensed at the surfaceof the liquid until the space is filled with saturated vapor intemperaturepressure equilibrium with the liquid. In reaching thisequilibrium, the pressure of the vapor in the space drops due to thecondensation of vapor and In carrying `out the hydrolysis of fats andoils by the countercurrent process in accordance with the presentinvention, vaporization of water within the apparatus to the extent thatit causes stirring or emulslcation is objectionable because itinterferes withthe operation of the process. The surface of thewater-containing liquid in the open top tank 4 being exposed to thesteam in the space in the upper part of the reaction chamber,vaporization of liquid water therein cannot be prevented unless thepressure of the steam exerted on the upper surface of the.liquids isequal to or in excess of the pressure of the saturated steam at theexisting temperature of the liquids in this part of the chamber. If thepressure of the steam in the upper part of the chamber is equal to thepressure of saturated steam at the temperature of the liquids in thispart of the chamber, the steam and liquid are in equilibrium, i. e.,they are in a stable state and there is no change in the relativequantities of steam and liquid present. On the other hand, if thepressure of the steam in the upper part of the chamber is in excess ofthe pressure of Vsaturated steam at the temperature of the liquids inthis part of the chamber, the steam and liquid are not in equilibriumand steam will condense, as already explained, and quickly establishtemperature-pressure equilibrium.

The pressure of the steam and the temperature of the incoming fattymaterial and water should be controlled, preferably automatically, sothat the `temperature in the reaction vessel may be held at the properpoint. In other words, if it is found that the liquids under processabsorb more or less heat from the surrounding steam, they, i. e.,l

simple means of the apparatus andmaintaining a constant and uniformtemperature throughout the entire length of the inner steam must be at asomewhat higher rate than the ilow outwardly through pipes l tocompensate for the condensation in the steam space. Moreover. since avpressure drop inevitably occurs in the direction of ilow. the incomingsteam must be at a somewhat higher pressure to overcome the iiow losses.In this way not onlyis the tempera.- ture throughout the entire lengthof the inner vessel maintained constant and uniform, but the pressure ofthe steam in the upper part of the reaction vessel is also maintainedconstant and in temperature-pressure equilibrium with the liquid.

The steam so provided will form an admirable cushion to offset thesurges ofthe incoming liquids supplied by reciprocating pumps.

I have found that Inconel is highly resistant to corrosion from fattyacids, although not as eifective as some of the vso-called stainlesssteels. However, it has a linear coeicient of expansion very close tothat of carbon steel, and I prefer to use it for this reason as a lineron the inside of the carbon steel shell to further protect it fromcorrosion in the event of any unforeseen foaming or boiling over of thecontents of the inner vessel. 'Howeven there are several otherlstainless steels or alloys which have approximately the same coeflicientof expansion as carbon steel and also relatively high corrosionresistant qualities, illustrations of which are type #446, chromium 23to 30%; type #430, chromium 14ste 18%; and type #431, chromium 14 to18%, nickel 2% maximum; and which may be employed asliners.

The contact of fatty acids with steel, under common conditions ofoperation, rapidly forms a sticky iron soap which is slowly washed downby the condensate, having a tendency to corrode the outer shell, whereasthe contact of fatty acids with Inconel" forms a very adherent soap lmwhich protects the vbalance of the Inconel" from further serious attack;furthermore, if some of the processed material should pass over into theannular space between the inner and outer shells, it can readily bedetected in the condensate and the free acids or fats may be easilyremoved before appreciable attack o'n the clad material occurs.

I have also found that the volatile acids generated and the steam havepractically no appreciable corrosive effect on"Inconel so that theexposed part of the outer shell I and the cover 2 may safely be linedwith this material.

Although the above description applies primarily to an apparatusespecially suitable for carrying out a process requiring high pressure.it is obvious that a similar construction may be used at any workablepressure, such as sub-atmospheric or high vacua for distillation orother purposes, since the equalization of the pressure inside andoutside the inner vessel may be maintained regardless of pressure.This`apparatus is well suited for the process of countercurrentlyhydrolyzing fats and oils by the use of water. such as is disclosed inthe Ittner patent hereinbefore referred to except, as will be clear fromthe foregoing, that inthis process of hydrolysis, as carried out in thisapparatus, the liquid material intheupperpartofthepressurevesselwillbein direct connection with the steamthat is supplied.

It is also possible to'use other mediums than steam, such as an inertgas. for equalising the pressure if itis impractical to use steam in theprocess involved.

Also, in processes'where there is no tendency I to foam or boil over.the trough l. drain pipes I and inverted collarll may be dispensed withand the inner corrosion resistant vessel constructed simply l5asanopentoptanhwithinan outershell.

It aan possible to dispens with the :nner

liner I, in the pressure vessel I. in using the apparatus for` certainpurposes, if it should be considered unnecessary.

scribed. 'I'he upper edge yI'I of tank I is fitted' with a recessed ringI8 in which are tted expan- A sion rings I8 which form a substantiallytight sliding seal against the inner liner l of the outer shell I.

Pipe 20 passing through the outer shell I below the sliding sealconnects the annular space I2 between the inner and outer shells withthe space below the cover 2 in such manner as to equalize the pressurewithin the several parts of the vessel,

as described above.

The leakage through the sliding seal will thus be minimized due to thesubstantially balan pressure above and below.

In cases where it is desirable to carry on a reaction in which thematerials must be kept away from any contact with steam or gas, I wouldf prefer to use an apparatus as shown in Figure 5, in which: I may bethe carbon steel pressure vessel tted with a cover 2, as previouslydescribed. f

The reaction portion of the apparatus consists of a vessel 2l with aclosed top, said vessel being either hermetically sealed or iitted withflanges (not shown) for the purpose of opening for inspection. Amongother functions, the top serves as a means to prevent any liquids frompassing between the ywalls of. the inner and outer vessels into spaceI2. In order to operate advantageously,

it is desirable to have the pressure on the outer side of the innerclosed reaction vessel slightly in excess oi the pressure inside of theinner closed reaction vessel. 'I'his may be accomplished by a suitableorifice 22 in inlet pipe I8 or a multiplicity ofv small orifices or jetsat the discharge end of pipe I8, or by other means. The differential inpressure and the relative rates oi' flow of water and fat may becontrolled by suitable valves 23 and 24, and the proportions of thedischarged materials may be controlled by suitable relief .valves 25 and28 which are preferably automatically operated.

The supply pipes 'I and I l and the discharge pipes 6 and I5 are sodesigned with expansion coils 21 or stuiilng boxes and glands (notshown) to allow the inner shell to expand freely.

In the application of the type of apparatus shown in Figure 5 to thehydrolysis of fats and oils, as described in Ittner United States PatentNo. 2,139,589, the space I2 surrounding the inner equalized through pipe28.

Loss of heat through radiation `may be compensated for in several ways.

Pump 28 may supply an excess of heated water over and above the amountneeded for saponiiication, and a constant flow of this heated water maybe maintained through the space I2 surrounding the inner vessel. Thisexcess water, having been slightly cooled by radiation from vessel I,may be returned by pipe 8 I to the pump Il after passing through areheater l2 whcreit is again heated to the desired temperature.

Also, loss of heat through .radiation may be compensated nfor by asuitable heating device 38, surrounding and in contact with the outershell I. This may consist of coils of pipe through which is passed hotcirculating liquids or vapors; or the heating device may consist ofelectric heaters of any suitable type.

In the event that a process requires the admixture of two or morecorrosive materials, so that it would be impractical to supply one ofthem through pipe I6, thus allowing a possible contamination throughpipe 28, a suitable equalizing device' (not shown) may be employed suchas a diaphragm chamber between pipes I8 and 28 to maintain the balance.Suitable pressure relief may be provided. as a relief valve attached topipe 28 (not shown) to prevent hydrostatic pressure from building up invessel I.

Also, an expansion chamber may be provided externally, if necessary, tocontrol the surges due to pump pulsations.

The arrows showing the direction of Ilow in Figure 5 show a preferredmethod of accomplishing the desired result.

Figure 6 shows diagrammatically a modification of the apparatus shown inFigure l or Figure 3. Instead of the open top inner tank as shown inFigures 1 and 3, that illustrated in Figure 6 is closed. In thisapparatus, saturated steam or other gas for heating is admitted throughpipe II to the space I2 between tank 4 and vessel I, which space I2 isconnected with the space above the liquid surface I4 in tank 4 by meansof connecting pipe 28, thus insuring the same' pressure within the tank4 as that within the space I2 between tank 4 and vessel I. Pipe 20passes through separator 34. fitted with a trap for removing anycondensate. Through pipe 86 vhich connects with pipe 2li additionalsteam may )e supplied to the system or may be removed '.herefrom. Thispipe 38 is equipped with valve I'I for appropriate control of additionto or renoval from a system of steam or gas. Pipe II s also equippedwith a trap 38 to facilitate renoval of any condensate from the space I2be- ;ween tank 4 4and vessel I. Thus. Figure 6 is adapted to a processin which equal pressure be- ;ween a gas which may be used for heatingandr the materials undergoing reaction for hydrolysis is maintained. Ashas been pointed out hereinbefore, this condition eliminates shock or uni usual strain caused by surges due to pumping pulsations.

Figure 7 is a modification of Figure 5 whereby the liquid to be added tothe interior of tank 4 (water in the case of hydrolysis of fats andoils) is supplied through pipe IIto the space I2 surrounding tank 4within vessel I and passes' through pipe 20 and then to pipe I8 fromwhich it is dischargedinto tank 4. A pipe 48 may be connected with pipesv2II` and I6 through suitable valves for further control of the supplyof water to inner tank 4. A T 39 connects pipes 'I and II and containsvalves therein by which the liquid introduced through pipe II may besupplied to tank 4 through pipe 1, or the contents of tank 4 may bewithdrawn through pipe 1, T 38 and pipe 4l; thus. further facilitatingthe filling or 15 emptying of tank 4. Steam or other gas may be suppliedto the space above the surface I4 of the liquid through pipe 4I and thusserve as a cushion, as explained hereinbefore. While in no way confinedtothe hydrolysis of fats and oils, an example of the operation of theapparatus for that purpose may be described briefly as follows: l

Referring to Figure l: assume the inner vessel to contain water up tothe line 42 and fatty material above the water to the line I4 and thespace above the line I4 and the entire space I2 surrounding the innervessel filled with saturated steam under pressure, for example about 640pounds, and the oil and liquid water being at a temperature known to besuitable for countercurrent hydrolysis, say 250 C.

`Outlet pipes 6 and I5 are fitted with suitable control valves (notshown) to maintain the proper operating pressure by release'of aqueousglycerine solution and fatty acids respectively.

Fatty material and water may now be pumped yinto the inner vessel,countercurrently in proper amounts and proper proportions continuouslyor in an intermittent or semi-continuous manner, with continuous,intermittent or alternate introduction of fatty material and waterthrough pipes 'I and I6 respectively.

'I'he fatty material will pass up through the bottom water layer whereit undergoes hydrolysis 45 to form glycerine and fatty acids. Theglycerine being soluble in the water will be retained there. and thefatty acids will pass on into the space indicated between 42 and I4,which will be largely composed of free fatty acids but which willinclude some unhydrolyzed oil or fat.

The water may be introduced at a distance somewhat below the uppersurface I4 of the fatty material through a multiplicity of orifices sothat it will pass down through the fatty material in a nely-dividedcondition, thus increasing the intimate contact between the water andthe fatty material. This will result in further hydrolysis of theunhydrolyzed oil in the upper layer. The glycerine formed thereby willbe dissolved in the water-as it passes down to the fatty material andwill be carried into the lower aqueous layer by the water in which it isdissolved.

This application is a continuation-in-part of my application Serial No.285,898 led July 22,

It is not intended that the foregoing shall be limiting in any senseupon the invention disclosed and claimed but it will be understood thatvariations therefrom may be made within the principles of my invention.

I claim: 1. In a countercurrent process for hydrolyzing fats withproduction of fatty acids and glycerine by bringing fat'and water intocontact with one another at a temperature above about 200 C. in.

an enclosed reaction chamber, the step of maintaining a substantiallyconstant pressure in the upper part of said chamber, suiilcient tomaintain the reacting fatty material and water as liquid phases whichcomprises supplying water vapor at a pressure in excess of the pressureof saturated steam at the reaction temperature to a vapor spacecommunicating with the upper part of the reaction chamber to form avapor cushion.

2. In a countercurrent process for hydrolyzing fats with production offatty acids and glycerine by bringing fat and water into contact'withone anotherat a temperature above about 200 C. in an enclosed reactionchamber, the step of maintaining a substantially constant pressure in"the upper part of said chamber, sufllcient to prevent and substantialevaporation of water in said chamber which comprises supplying saturatedsteam at a pressure in excess of the pressure of saturated steam at thereaction temperature to a vapor spacein the upper part of the reactionchamber to form a vapor cushion'.

3. In a process for hydrolyzing fats with production of fatty acids andglycerine by bringing fat and water into contact with one another at atemperature above about 2007 C. in an enclosed reaction chamber, thestep of maintaininga sufllcient pressure in the upper part of saidchamber to maintain water in the liquid condition at all times bysupplying water vapor at a pressure in excess of the pressure ofsaturated steam at the reaction temperature to a vapor spacecommunieating with the upper part of the reaction chamber to form avapor cushion, the temperature and pressure being below that at which asingle liquidI phase is formed.

4. In a continuous process for hydrolyzing fats with production of fattyacids and glycerine by causing the fat and liquid water to pass incountercurrent direction in contact with each other at a temperatureabove about 200 C. in a vertical reaction chamber, the step ofmaintaining a constant pressure in the upper part of said chamber inexcess of the pressure of saturated steam at the reaction temperature,which comprises supplying the upper part of the reaction chamber withwater vapor to form a vapor cushion. and releasing from the chamberexcess water vapor above that required to maintain the said pressure.

5. In a continuous countercurrent process for hydrolyzing fats withliquid water at a temperature above about 200 C. in an enclosed reactionchamber, the steps of maintaining at all times a steanr cushion in theupper part of the reaction chamber by the introduction of steam at apressure in excess of the pressure of saturated steam at the reactiontemperature, and releasing from quired to maintain the steam cushion ata pressure sumcient to maintain the reacting fatty material and water asliquid phases.

6. Ina continuous countercurrent process for hydrolyzing fats at atemperature above about 200 C. in an enclosed chamber, the steps ofcreating and maintaining a cushion of water vapor communicating with theupper part of the chamber to absorb pressure pulsations from the liquidfeed pumps, said vapor cushion being maintained at a pressure in excessof that of saturated steam at the reaction temperature.

7. In a process for hydrolyzing fats with production of fatty acids andglycerine by causing fat and liquid water to ilow in countercurrent'direction in contact with each other at a temperature above about 200 C.through a reaction zone, the steps of maintaining a constant and uniformtemperature throughout the reaction zone, and a constant and uniformpressure on the liquids in said zone which comprises supplying steam ata pressure in excess of the pressure of saturated steam at the reactiontemperature to a vapor space .around ithe reaction zone .and incommunication with the liquids therein.

8. In a process for hydrolyzing fats the steps 'l which comprisecontacting fat with liquid water` by countercurrent flow at atemperature above about 200 C. in a hydrolyzing chamber and maintainingsubstantially uniform pressure on the fat and water in the hydrolyzingchamber by supplying steam at a controlled pressure in excess of thepressure of saturated steam at the reaction temperature to a space abovethe reacting materials and in contact therewith.

9. In a process for hydrolyzing fats the steps which comprise contactingfat with water in liquid phase by countercurrent ilow at a temperatureabove about 200" C. in a hydrolyzing cham- 0 ber and introducing steamat a controlled preschamber by continuously introducing steam at a thechamber any excess steam above that re-l controlled pressure in excessof the pressure of saturated steam at the reaction temperature to aspaceabove the reacting materials and in contact with the upper surfacethereof and continuously releasing from said space excess steam.

WARREN DAVEY.

